Chen Guangcheng, the blind Chinese legal activist, arrived smiling at Chaoyang Hospital, a sprawling redbrick complex, on Wednesday afternoon. It was supposed to be a triumphant resolution to the diplomatic crisis that started six days earlier when Mr. Chen sought protection in the U.S. embassy, a precursor to a new life studying law in China.

U.S. Ambassador Gary Locke stayed for 90 minutes and met with Mr. Chen's wife and children, who had sped to Beijing on a high-speed train.

Then, as darkness fell, a growing number of police arrived at the ninth-floor corridor. They took video of visiting journalists before jostling them into elevators. At 6:30 p.m., hospital staff asked the remaining U.S. officials to leave. They said visiting hours were over.

Suddenly, the people who had protected Mr. Chen were gone.

Blind Chinese activist Chen Guangcheng holds a petition.
Reuters

That development helped send the activist into a panic, precipitating a crisis that derailed the agreement, prompted days of confusion and recrimination, and cast a pall over U.S.-Chinese relations.

Around 9 p.m., Mr. Chen told a friend by phone the hospital had given the family nothing to eat. Others phoned and one friend urged him to reject the deal. Mr. Chen told callers he had been coerced to leave the embassy and was worried for his family's safety. He tried calling two embassy officials around 10 p.m. Neither answered.

The Chen saga, based on interviews with government officials, activists and others in the negotiations, began with the promise that American relations with China had entered a new, mature phase. It ended demonstrating how much distance and suspicion remain between the two powers.

Mr. Chen stands with wife and son, middle, while living in Shandong province
Associated Press

Friday, both sides appeared close to a fresh deal that would bring Mr. Chen and his family to the U.S., probably to study law at New York University. With final details not yet signed, U.S. officials said they were confident the deal would work out. Some analysts saw the quick agreement as a sign the bilateral relationship was resilient. The damage, however, especially from that Wednesday night at the hospital, had already been done.

U.S. officials, in their rush to complete negotiations Wednesday before a separate set of high-level U.S.-China talks was set to begin, appeared to have misjudged Mr. Chen's fragile emotional condition.

The self-taught activist had spent four years in jail—on trumped-up charges, critics say—and 19 more months in home detention, where he says he endured periodic beatings, before his dramatic dash to the embassy.

The days were filled with missed calls and dropped connections that might have changed the trajectory of events.

This week, Mr. Chen with State Department official Kurt Campbell and, between them in rear, U.S. Ambassador to China Gary Locke.
Reuters

It's also possible the U.S., in negotiating with China's foreign ministry, overlooked the country's competing power centers jockeying for position. The foreign ministry has traditionally carried little clout in the Chinese power structure, and analysts say the fate of Mr. Chen was almost certainly decided by top Communist Party leaders. Mr. Chen seemed worried mostly about his fate at the hands of China's security services and provincial officials.

U.S. officials, for their part, felt Mr. Chen turned on them after hours of negotiations, one calling him "self absorbed." Mr. Locke, the U.S. ambassador, complained about the activist's change of heart, according to a senior administration official who spoke with him. Mr. Locke "feels like the guy is unfairly attacking the U.S.," the official said.

Mr. Chen rose to prominence in activist circles as a critic of forced abortions and sterilizations in his home province under China's one-child policy. His campaign led to the firing of local officials and brought about his run-in with authorities.

He slipped away from home detention the night of April 22, scaling at least eight walls, according to activists involved and a U.S. account, injuring a foot in the process. It took him 20 hours to move through his local area before he could meet up with a fellow activist who drove him from Shandong province to Beijing.

Once there, they moved from safe house to safe house before contacting the U.S. embassy. They rendezvoused with U.S. personnel, who escorted him into the embassy on April 26.

The U.S. was silent on his whereabouts, although it was an open secret; activists said they were told he was in the "safest place in Beijing," code for the embassy.

A senior State Department official said Mr. Chen's injury was the main impetus for granting him admission, a move all parties knew would spark a diplomatic furor. The decision involved "the highest levels of the State Department," one senior U.S. administration official said. He said U.S. delegation in Beijing was in regular contact with the White House.

The White House's National Security Council was briefed on the situation by the State Department, but President Barack Obama wasn't told before Mr. Chen was brought into the embassy, a senior administration official said.

The Chinese side in the negotiations was led by Cui Tiankai, a vice minister of foreign affairs. Mr. Cui, fluent in English, is well regarded in Washington. Urbane and impeccably dressed, he is at ease with the foreign media.

Kurt Campbell, an Assistant Secretary of State, took the helm for the U.S. A former naval officer and academic, he has sought to strengthen the U.S.'s non-Chinese alliances in Asia but refers to his counterparts in Beijing as his "Chinese friends."

Mr. Chen spoke to Ambassador Gary Locke on Wednesday.
Getty Images

Overhanging the talks was the U.S.-China Strategic and Economic Dialogue, an annual series of talks, which was to begin Thursday. U.S. officials were nervous any impasse could derail the meeting.

A battery of U.S. officials, led by the ambassador, spent hours talking with Mr. Chen to determine what he wanted. Mr. Locke said he spoke to him for an average of three hours a day. U.S. officials shared their personal experiences, and Mr. Chen talked about other famous activists, including Burmese democracy icon Aung San Suu Kyi. He concluded that carrying on his fight outside China would be difficult.

U.S. officials said Mr. Chen told them he wanted to reunite with his family, relocate to a safe place somewhere else in China, study law and have the Chinese government investigate his allegations of mistreatment.

On Monday, Mr. Chen spoke with Jerome Cohen, co-director of New York University's U.S.-Asia Law Institute, a longtime human rights advocate. Mr. Chen told him it appeared risky to leave the embassy. "I told him just to hang in there because over time he could work something," Mr. Cohen said.

Mr. Chen rode in a car with Mr. Locke en route from the U.S. embassy in Beijing to a hospital on Wednesday.
Associated Press

The next day, Mr. Cohen recalled, they talked about the pros and cons of staying in China. Mr. Cohen offered him a spot at NYU.

With Secretary of State Hillary Clinton en route for the strategic and economic talks, the Chinese government "gave us a response," Mr. Locke said. It would have meant Mr. Chen leaving the embassy while his family was still in his home province.

Mr. Chen said no. Embassy officials started working on the logistics of housing for Mr. Chen inside the embassy if necessary.

Then, later that night, he asked that his family be brought to Beijing as a signal of good faith by the Chinese government, which agreed. The plan was to give Mr. Chen a chance to speak with his wife and "enable him to make a very final decision" about leaving U.S. protection, American officials say.

Mr. Chen was reunited with his wife and children at the hospital. An initial plan for Mr. Chen to stay in China fell through but the sides negotiated a new plan under which the family would come temporarily to the U.S.
AFP/Getty Images

On Wednesday, Mr. Chen asked to speak with Rep. Chris Smith, a New Jersey Republican, and Democratic Rep. Nancy Pelosi of California. Mr. Smith thought the emerging deal was a terrible idea, and wanted to tell Mr. Chen to instead come to the U.S.

He called the State Department operations center but couldn't get through. He stayed up until 4 a.m. waiting for a call. By the time a department official called back, Mr. Chen had left the embassy.

By this time, Mr. Chen's wife and children were at the hospital. Twice she spoke with her husband. Mr. Locke said she "implored" Mr. Chen to leave the embassy and join the family at the hospital.

The ambassador and State Department officials huddled around Mr. Chen, who likes to hold people's hands while talking to them. They asked him what he wanted to do—did he want to leave?

"We waited several minutes. And then he suddenly jumped up, very excited, very eager, and said, 'Let's go,' " Mr. Locke said, an account echoed by other U.S. officials. It was after 2 p.m. on Wednesday, almost six days since Mr. Chen came to the embassy.

Before they got in the van, Mr. Locke asked him again, "Is this what you want to do? Are you ready to leave?" Mr. Chen said yes.

Once in the van, U.S. officials realized they didn't have their cellphones, because they had been in the secure part of the embassy. Borrowing a staffer's phone, they called Mrs. Clinton. Mr. Chen said in Chinese how grateful he was for her support. Then, in broken English, he told her he "wanted to kiss her."

U.S. officials described it as a touching moment, but Mr. Chen immediately regretted the remark. To cover his tracks, he later told people he had just said he wanted to "see" her.

Mrs. Clinton released a statement saying she was pleased "we were able to facilitate Chen Guangcheng's stay and departure from the U.S. embassy in a way that reflected his choices and our values." Exhausted U.S. officials, who had barely slept for a week, described the arrangement as a triumph of diplomacy.

That's when the carefully laid plans went awry. The U.S. had made no arrangements for embassy personnel to spend the night at the hospital. Officials spoke with Mr. Chen by phone two more times that evening. Then he started getting calls from friends and fellow activists.

Teng Biao, a human-rights lawyer and Chen confidant, advised him to reconsider. "Their revenge may have already started: They still haven't given us dinner," Mr. Chen told Mr. Teng in a call at 9 p.m. Wednesday, according to a transcript posted on Mr. Teng's personal blog. "The children are crying from hunger." Mr. Teng said he told Mr. Chen's wife, Yuan Weijing: "As soon as the Americans are gone, you'll be in danger."

Zeng Jinyan, a prominent Chinese activist, said she also spoke to Mr. Chen by phone and found him growing increasingly agitated, according to her Twitter account, asserting that Mr. Chen had left the embassy only because of threats leveled at this wife. The U.S. denied relaying any threats to him. Mr. Chen told a bevy of news organizations he now wanted to leave the country.

U.S. officials dismissed the reports for hours. After midnight in Beijing, the State Department released a statement denying the snowballing allegations.

Enemies of the State

Some notable Chinese dissidents.

Mr. Chen's change of heart left the U.S. diplomacy looking naive. Critics began to speculate that U.S. officials had scared him into leaving so as not to jeopardize the economic talks. Mitt Romney said that "If the reports are true,…it's a day of shame" for the administration.

On Thursday, U.S. officials scrambled to defend their actions. There was one complicating factor: The U.S. didn't have the access to Mr. Chen it had anticipated. U.S. embassy officials couldn't see Mr. Chen in person. Instead, they met his wife outside the hospital in the morning.

The economic and strategic summit, meanwhile, kicked off without a hitch. Mrs. Clinton made her opening statement, including a short reference to human rights, in the ornate Hall of Flowers at the Diaoyutai State Guest House—a compound, once a favorite fishing spot of Chinese emperors, that was also the site of the 1972 talks that reopened U.S.-China relations.

By 5:30 Thursday afternoon, the State Department acknowledged Mr. Chen had changed his mind. U.S. officials tried to connect with Mr. Chen by phone Thursday night in the hospital, but again were unsuccessful.

Others had more luck. In what appears to have been a critical phone call, Mr. Chen spoke near midnight to Guo Yushan, a scholar who aided his initial flight. The tone of the conversation was markedly different from the frantic calls of the day earlier. Mr. Guo, in an Internet posting, conveyed a new message from Mr. Chen, including an apology for "the pressure brought to the relevant parties including the U.S. embassy."

Mr. Guo wrote: "He wants to go to the U.S. for travel for a while and then come back. Therefore, this is not a change of mind."

A couple of hours later, Mr. Chen had an open microphone to the U.S. Congress. It was the middle of Washington's afternoon, and Bob Fu, who runs the Christian advocacy group ChinaAid, was testifying at a hearing called by Rep. Smith to discuss the brouhaha. Mr. Fu dialed Mr. Chen and held up the phone for all to hear.

Messrs. Smith and Fu discussed the call during a break. Mr. Smith said he "took a minute to think: does this help or hurt him. I figured this would give him further protection."

Broadcast live, Mr. Chen broached the idea that he had discussed with Mr. Guo but that was news to everyone else: temporarily leaving China, with the whole family, to rest and maybe study at a U.S. university.

On Friday, the summit continued as planned. Mrs. Clinton had a whirlwind of meetings with top Chinese officials and dashed across town to another event to tout closer ties between American and Chinese people.

Still, there was no easy way out. By early afternoon on Friday, U.S. embassy officials still hadn't been able to meet with Mr. Chen face to face in the hospital.

Then, suddenly, the Chinese Foreign Ministry put out a simple statement on its website. Mr. Chen, it said, could apply to study abroad like any Chinese student, as long as he followed procedures. Standing in sharp contrast to the tone used earlier, it seemed China was preparing to meet Mr. Chen in the middle.

"My eyes lit up like a pinball machine when I saw that, because that's the way out of the crisis," said Mr. Cohen, the NYU professor. He called it an "exciting, low-key, dignified" solution for both governments.

A few hours later, Mrs. Clinton, Treasury Secretary Timothy Geithner and two Chinese officials—Vice Premier Wang Qishan and State Councilor Dai Bingguo—took the stage to close the two-day affair.

Mrs. Clinton thanked her hosts, reviewed some achievements, then spoke of areas where China and the U.S. still disagree. "Of course, the United States continues to raise human rights, because we believe they are essential for every country to uphold," she said. "And we raised specific matters of individuals and situations whenever necessary," she added.

Christian activist Bob Fu learned of Chen Guangcheng's growing agitation over his situation in a hospital in Beijing on Wednesday from a Twitter post from another activist, Zeng Jinyan. Citing Mr. Fu, an earlier version of this article incorrectly said Ms. Zeng directly emailed Mr. Fu.